In the middle of designing a dust collection system, a fellow associate asked if the main trunk line could be on the ground. Our current dust collector's inlet points straight up at 9" in dia. This would require three 90deg elbows to immediately after my inlet to get the main line on the ground. I am concerned by this adding to much drag on the dust collector having so many 90deg elbows right out of the inlet. What do you think?
From contributor JR
You are right that it will add resistance, but being in the largest diameter section, it may not hurt too badly. I guess it depends on whether having the trunk on the ground will allow shorter runs of smaller diameter branches with fewer elbows. If so, then it might be worth it. A back-of-the-napkin calc using Air Handling's resistance/design charts will give you a better idea.
From contributor Je
Is it a cyclone? If so your supposed to keep the trunk straight for at least several feet before changing direction.
I'm assuming since it points straight up it's not a cyclone and your dealing with a regular collector. If so your probably fine changing direction. I wonder why you would want the trunk on the ground though? Unless your going under the floor your going to have a bunch of pipes on the ground which are trip hazards. Not to mention they'll likely be more prone to getting damaged being on the ground vs at the ceiling as is normal.
good luck,
Jeffd
From contributor Cu
James,
As I recall, some of the blower and filter bag type dust collectors will allow you to flip the blower over. Check the feasibility of this where the blower connects to the filter bag plenum. Possibly, it can be done with a minor modification. Then, you will only need one 90 deg elbow if running main on floor will create less pipe runs, etc. as JR mentioned. One 9" 90 degree elbow with a centerline line radius of 1 1/2 X diameter is equal to 18 feet of straight pipe in equivalent resistance.
Curt
